1. Field of the Invention
Methods and devices consistent with the present invention relate to a pointing system and, more particularly, to a multi-pointing method using a magnetic field and a system therefore.
2. Description of the Related Art
Existing pointing systems include a system using light, a system using a touch screen, a system using an ultrasonic wave, a system using a radio frequency (RF) signal, and the like.
In the system using light, when a user designates a predetermined location on a display device by using a light gun, the location is sensed by using a display timing of a CRT scanning line. The system using light is supported by only CRT display devices.
In the system using the touch screen, when a surface of a display device is pointed by using a finger or stylus pen, the pointed location is sensed through a pressure sensing device. In general, the system using the touch screen cannot receive a plurality of pointing locations at the same time. When there is another object on the surface, the system using the touch screen is influenced by a pressure of the object.
In the system using the ultrasonic wave, an ultrasonic wave is generated in the periphery of a display device, and a pointing device gathers the ultrasonic wave and calculates a distance. Alternatively, the pointing device generates the ultrasonic wave, gathers the ultrasonic wave in the periphery of the display device, and recognizes the distance. In general, the system using the ultrasonic wave cannot receive a plurality of pointing locations at the same time. When there is another object on the surface or in the periphery of the pointer, the system using the ultrasonic wave is influenced by the object.
In the system using the RF signal, a location of a pointing device which generates an RF signal is recognized from a plurality of RF receiving units using resonance. The system using the RF signal can receive a plurality of pointing locations at the same time. However, because a plurality of RF receiving units are needed, costs are relatively high.
As discussed above, some of the existing pointing systems cannot provide a multi-pointing operation. On the other hand, in the existing pointing systems which can provide the multi-pointing operation, the costs are high.